Circuit maker



July 3, 1951 o. JENSEN CIRCUIT MAKER Filed April 20, 1945 5 Sheets-Sheet 1 INVENTOR. OTTO JENSEN m-rozz vsys 3, 1951 o. JENSEN 2,559,216

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Filed April 20, 1945 5 shuts-shes; 2

INVENTOR. arro JENSEN BY ATTORNEYS July 3, 1951 o. JENSEN CIRCUIT MAKER Filed April 20, 1945 ZSI 5 Sheets-Sheet 3 mmvrox OTTO JENSEN ATTORNEYS July '3, 1951 o. JENSEN 2,559,216

CIRCUIT MAKER Filed April 20, 1945 5 Sheets-Sheet 4 nvvuvron OTTO JENSEN zrrnnNEYS 0. JENSEN CIRCUIT MAKER July 3, 1951 5 Sheets-Sheet 5 Filed April 20, 1945 FZummDO :00 nzmk.

J my w W w A INVENTOR. firra Janm I I H k R MN @UL DOw P tented July 3, 1951 UNITED STATES PATENT OFFICE,

CIRCUIT MAKER Otto Jensen, Malvern, Pa., assignor to I. T. E. .Circuit Breaker Company, Philadelphia, Pa,

a corporation of Pennsylvania Application April 20, 1945, Serial No. 589,344

. 1 Claim. (01.200-87) My present invention relates to switchgear, and more particularly to a circuit maker designed to close a circuit rapidly'on the occurrence of predetermined conditions.

The usual form which a quick operating switch takes is that of a eircuit breaker in which the problem is to open the circuit as quickly as possible when ahigh fault current occurs.

In the present invention, the problem is reversed, that is, the quick operating switch is designedto close a circuit on the occurrence of high fault current.

Essentially my device is designed for use in connection with a circuit interrupter to provide a discharge path for high reactive loads or to short circuit the generator or similar device which has its field cut oil. Thus, where the circuit to a large magnet is interrupted, the high reactance of the load may cause an excessive voltage rise owing to the sudden interruption. The operation of my circuit maker to close the circuit across this load and to provide a discharge path for the current ensures that the entirecircuit will not be subject to the disruptive forces of this excessive voltage rise. My novel circuit maker may thus be used to provide a by-pass circuit to discharge this current or to introduce a resistance to reduce the momentary voltage rise.

In the usual circuit breaker, the contact is a movable member bridging two studs, and the electric circuit within the circuit breaker is preferably U-shaped, with the contacts so spaced and shaped that the magnetic field due to very high currents tends to blow the circuit breaker open thereby speeding the opening of the circuit breaker. In the case of my novel circuit maker, the exact reverse of this type of operation is required; it is desirable to close the circuit maker on very high values of current. The values of currents for which the novel devices according to my invention have been designed are 30,000 amperes, 100,000 amperes and 200,000 amperes.

In order to be able to close the contacts of my device under these very high currents, I have found that best results are achieved by the novel expedient of forming the electrical circuit loop so that the contacts will be driven at all times to the closed position under the influence of the magnetic field created by the very high current. To this end, the electrical circuit within my novel circuit maker is so designed that the contacts operate on the inside of the loop.

,. The circuit maker is normally in the open position and is held in that position by a latch. It is biased toward the closed position by heavy springs acting directly on the contacts. The direct acting spring pressure on the contacts combined with the positioning of the contacts on the inside of the current loop provides a very fast closure.

Essentially, therefore, my circuit maker is a switch which is normally latched open and is subject to continuous biasing pressure tending to close it. The operation of a trip coil releasing the latch will permit the biasing means to eflect a rapid closure of the circuit maker.

Accordingly, a primary object of my invention is the provision of switchgear which is biased toward circuit closing position but which is normally latched open.

.Another object of my invention is the provision of a circuit maker which will close a circuit at high speed in response to predetermined current conditions.

Still another object of my invention is the provision of a circuit maker so arranged that the contacts are under direct biasing pressure tending to close them.

A further object of my invention is the arrange- 'ment of the electrical connections and contacts of the circuit maker in such a manner as to form a current loop tending to blow the contacts together.

These and many other objects of my invention will become apparent in the following description and drawings in which:

Figure 1 is a side view of my novel circuit maker showing the contacts tripped closed and before a resetting operation has taken place preparatory to reopening the circuit maker.

Figure 2 is a front view, partly in section, taken from line 22 of Figure 1 looking in the direction of the arrows.

Figure 3 is a' side view corresponding to that of Figure l with the side cover removed showing the elements of the circuit maker in the same position as that of Figure 1.

Figure 4 is a schematic view of the link mechanism of the circuit breaker of Figure 1 showing the circuit breaker trip closed and the link elements reset preparatory to a contact opening operation.

Figure 5 is a schematic view corresponding to that of Figure 4 showing the movement of the contacts from the Figure 4 position to the open circuit position.

Figure 6 is a schematic view corresponding to Figure 1 showing the contacts once more in the tripped position of Figure 1.

Figure 7 is a schematic circuit diagram showing the manner in which my novel circuit maker may be used.

Figure 8 is an oscillogram demonstrating the operation of my novel circuit maker.

Referring now to Figures 1, 3 and 6, the circuit maker is here shown in the tripped position where the contacts have been tripped closed and before the link mechanisms have been re-set preparatory to a circuit opening operation.

Current enters the circuit maker through the connection bar it and passes up to the connecting block H, which is secured thereto in any suitable manner. The connecting block II is provided with a plurality of grooves in which are secured the connection studs [2, l2 (see also Figure 3).

The connection studs I 2, I2 are held in appropriate position in the grooves by a plurality of bolts H, l4 passing through the connecting block H in the grooved area thereof and the connecting studs l2 carried in those grooves. The bolts also pass through the outside tie-plates l6, one on each side, and are appropriately secured by nuts I1 and washers l8 on each side.

Pivot rod l9 passes through aligned openings in each of the connecting studs 12 and carries a plurality of pairs of contact arms 20 rotatably mounted thereon.

Each pair of contact arms 20, as is seen in Figure 2, is mounted on opposite sides of a connecting stud I2. The sides of the,contact arms 20 are forced into close current carrying engagement with the respective connecting studs l2 with which they cooperate by the spring wash- I ers 22 between each pair of connectingarms 20.

The entire assembly is forced into tight current carrying engagement by bushings 24-24 mounted on each end of the pivoting rod I9 and forced against the spring washers 25, 25 by nuts 26, 25. Each of the nuts 26 has a locking extension 28 extending outwardly therefrom provided with a plurality of grooves 29, 29. Cotter pin 30, passed through an opening in each end of the rod l9, passes through a pair of opposite grooves 29 in the locking extension 28 and prevents the nuts 26 from rotating to loosen the established current carrying connection.

Each of the contact carrying members 20 carries an individual main contact secured thereto in any appropriate current conducting manner. As is seen in Figure 2, each of the contacts 35 is wider than the contact carrying arm 20 which carries it so that the contacts are spaced from each other by relatively small distances, and'substantially the entire width of the stationary contact 40 is thus effectively used.

secondary contacts 4| are each supported on secondary contact carrying arms 42, which in turn are each carried between respective pairs of main contact arms 20, 20, as is seen in Figure 2. The secondary contact arms 42 are each pivotally mounted on the rod 45 which pass through aligned openings in the upper ends of the arms 42 and corresponding openings in the lower ends of the arms 20.

The rod 45 is provided with a lock nut 46 corresponding exactly to the lock nut 26, above described in connection with rod i 9, the said lock nut having an extension 41 with grooves 48 to receivethe cotter pin 49 and to prevent the lock nut 46 from turning once it has been tightened.

Spring washers 50 are provided at the lower end' of the contact arms 2i] between pairs of contact arms 20 surrounding the rod 45 and pressing the pairs of contact arms 20 together at their lower ends to ensure an efficient current carrying condition between the lower ends of the contact arms 20 and the upper ends of the secondary contact arms 42.

The main contacts 35 and the secondary contacts 4| cooperate respectively with a'longitudinal main contact member 52 .and a longitudinal secondary contact member 53 on the stationary contact block 40. This arrangement of the movable main and secondary contacts provides for a degree of flexibility for the contact structure, so that if the stationary contacts or portions of the main contacts should become worn, the remaining contacts may adjust themselves to a limited degree to the slight variation from a planar condition. I

The current then flows from the stationary contact block 40 to the opposite connecting member 55. It will thus be seen that within the circuit maker itself, a current loop is formed comprising the connecting member ID, the connecting block H, the connecting studs I2, the contact arms 20 and 42, the contact'block 40 and the connecting member 55.

It will also be seen that the contact arms 20-42 with the movable contact members 35 and 4| are pivotally mounted to swing inside the loop It, H, [2, 20, 40 and 55.

A contact blow-on effect is obtained by reason of the curve of the loop around the pivot point i 8, and also by reason of the fact that the contact arm 20 must swing out in a direction toward the outside of the loop in order to close the contacts. In the ordinary quick acting circuit breaker, just the opposite effect is desired, and the contact arms are arranged so that they are pivoted to swing away from the loopwhen' contact opening is desired, and they swing in to close up the loop during contact closing. Thus, in circuit breakers, a contact blow-off eflect is desired and obtained.

In my novel circuit maker, the U-shaped electrical circuit with the contact members on the inside of the loop and swinging out during contact closing condition obtains a blow-on eiTect tending to reinforce the biasing means which closes the contacts of the circuit maker. By this combination of the biasing means for moving the contacts and the blow-on effect, an extremely rapid contact closing operation is obtained, and contact engagement is assured.

The biasing means comprises a plurality of, compression springs 60, G0 guided by the rods 5|, 6! which pass through appropriate openings in the connecting member ID and the cross bracket 62. The rods 8|, 6| are connected to the lugs 63-63, which in turn are pivotally connected to the cross rods 64-64 which pass through a plurality of aligned openings in the contact arms 20 (see also Figure 2).

The compression springs 60 bear against the left hand surface (Figure 3) of the lugs 63 at one end and against the right hand surface of connecting member in at the other end. These compression springs accordingly exert a strong bias on the contact arms 20 tending to rotate them in a counterclockwise direction to effect the closing of the circuit maker.

The secondary contact arms 42 are also provided with lugs 10 pivotally mounted on the rods II-H passing through aligned openings in the secondary contact arms 42.

Each lug 10 carries a guide rod 13 which passes through an opening in the connecting member I6. A compression spring 16 is mounted between the right hand surface or the connecting member I6 and the leit hand surface of the lug and thus independently biases the secondary contact arms 62 into circuit closing arrangement.

Each lug 66 supports a pair of compression springs 60-60 and guide rods 6I-6-I. The lugs 66 are pivotally connected to each pair or main contact arms through the individual cross rods 656-46 which are retained by the cotter pins 65-6 a This type of construction is used to secure even contact pressure throughout the width of the contact 60 since a solid rod would permit only the highest contact members 65 to exert proper pressure.

A similar construction is used for the same reason with the secondary contact arms 62, lugs 10-10 and the cross rods 1I1I retained by the cotter pins 1212.

When the high currents, above mentioned, are passing through the connecting members I0 and 55, veryhigh magnetic forces are provided tending to force the conducting members I0 and 55 apart owing to the loop shape or the circuit. For that reason it is necessary to place the conductors with respect to each other in a very rigid manner. Accordingly portions 01' the connecting members I0 and 55 that extend toward the bottom of the circuit maker as passed through balks 11, 16 which are insulated i'rom the conductors, and the conductors are very .rigidly mounted in a heavy frame. The conductor I0 is braced by the bracket 62 and the cross bracket 16, and the conductor 55 is braced by the cross bracket 60 and the insulating cross member 6|.

The balks 11 and 16 each comprise a bolt 65, 65' having insulating sleeves 66-66 and mounted through aligned openings in the connecting members I0 and 55. An insulating bushing 66, 66' ismaosunted on the sleeve 66-66 of each bolt 65- Nut 60 is tightened on the bolt 65 against washer 6| which bears against the conducting member I0. Accordingly. the bolt 65 is at the potential of conducting member I0. The opposite end of the bolt 65 at nut 66 is completely insulated from the connecting member 55 by the extended bushing 66, so that nut 63 is tightened against washer 65 against the end of the bushing 66 and is thus electrically isolated from the conducting member 55.

At the upper bolt 65, the cross piece 6| of insulating material takes the place of the bushing 66 at the lower bolt 65. All of the mechanism may be at the potential of the connecting member I0. The connecting member 55 is insulated from the remainder of the mechanism by the bushing 66, the cross piece 6I of insulating material and the upper insulating bushing 66'.

Appropriate current connection may be made to the connecting members I0 and 55 by connectors I00 secured to the connecting members I0 and 55 in any suitable manner as, for instance, by bolts passing through the aligned openings I0 I The entire apparatus hereinbeiore and hereinafter described is preferably mounted on a pair of vertical angle brackets I05 (Figure 2) which are secured in any uitable manner, as by the bolts I06, to the panel I01. The angle brackets I65 may be secured or may be integrated with side supporting panels I06 which are bridged at their outer end by the reinforcing support I06 to rigidity the structure, which Is also bridged 6 and rigidiiied by the main pivot rod I6 tor the main contact arms, as well as by the brackets 62, 16, 202, 2I0, 2 I|, 20I, 60.

Referring now to Figure 5, the contact arms 20 are retained in the open position against the bias of the compression springs 6| and 16 by the linkage system IIO. The linkage system I I0 comprises a main toggle III including links II2 and I I2a connected by the centerpin I I6. The outer end 0! link II2 is pivotally connected to the rod 6 which passes through aligned openings in the main contact arms 20 and is secured in position by the cotter pins II5-II5 (see also Figure 2). The outer end of link II2a on the opposite side is connected by the cross rod II6 to the operating arm II1.

In the open position of the circuit maker shown in Figure 5, the toggle III is just slightly above center so that it tends to collapse with the center pin II6 mov upwardly under thetintluence of springs 6| and 16. This upward collapse is, however, resisted by the latching link I20 which carries a latch engaging roller I2I engaging the latch member I22. Latch member I22 is secured to the rotatable support I26 carried between the side plates I06.

Latch member I22 has an upper extension I25 in the path or movement of the tripping bar I26.

The tripping bar I26 is mounted in a pair of aligned horizontal slots in the opposite side plates I06 and is maintained in position'by suitable cotter pins.

A side bracket I21 mounted on the outer surface of each of the plates I06 is provided with a matching slot for movement of the tripping bar I26 and with an adjustable stop member I26 to limit the movement of the tripping bar I26.

The trip bar I26. extends through to the outside o! each of the side plates I06 where it may be engaged by suitable means and moved to tripping position.

An armature I30 is pivotally mounted at I3I on the outside of one of the side plates I08. The armature I60 has an extension I62 engageable with the left side of thetripper bar I26.

A magnet I in series with the circuit protected by the circuit maker is arranged so that when appropriately energized it will attract the armature I 60. The armature I is biased away from the magnet I byvthe tension spring I66 which engages the armature I60 at the pin I31 and which, at its opposite end, engagesa stationary lug I66.

The magnet and armature assembly with the spring I36 may be made as a single unit mounted on the bracket I60 securable to the outside of one of the plates I08 in a position where the lower extension I32 of the armature may engage the tripper bar I26 when the armature is attracted by the magnet I65.

When the magnet has been energized by appropriate current conditions to overcome the tension of spring I66 and attract the armature I60, the lower extension I62 of armature I60 will be rotated counterclockwise to bear against tripper bar I26 which in turn bears against the upper extension I25 oi the latch member and rotates the latch I22 clockwise around its pivot I26 so that it will disengage the latching unit I2I on the latching link I20. I

The latching end I2I of the latch link I20 is supported and guided by the guide link I50 which is pivotally mounted on the main pivot I5I around which the operating arm III rotates. The intermediate am 226 is connected to the through a slot I90 in the panel I01.

toggle I55 which comprises linksISS and I51 connected by the center pin I58. Link I55 is connectedat the pivot I59 to the intermediate arm 220, "while link I51 is rotatably connected to the stationary pivot II carried by the frame of the mechanism.

In the extended osition of the toggle I55, the center pin I58 has moved slightly above center so that the toggle has a tendency to break upwardly. This upward breaking of the toggle on movement through center is prevented, however, by extension I of link I51 which bears against the underside of abutment I1I of link I56.

When the circuit maker trips from the position of Figure 5 to the position of Figures 1, 3 and 6, it is necessary to re-set the latches before the circuit maker can be opened once more. The latch re-setting operation is performed by a handle member I8I which engages with the extension I80 of toggle link I51. The handle, shown in dotted lines at I8I of Figures 3 and 1, is inserted in a socket I83 of the extension I80 of link I51. Lifting the handle,. I8I raises the end I80 of the socket and depresses the center pin I58 of the toggle I55, breaking the toggle downwardly; this re-engages the latch member I22, as shown in Figure 4. Rotation of member II1 to relatch toggle III is-assisted by tension spring H8 attached at one end to the center I I4 of toggle III and at the other end to the lug II9 mounted on a stationary pivot.

Lowering the handle I8I lowers. the end I80 of link I51, raising the center pin I58, and thus extending the toggle fromthe position shown in Figure 4 to the position shown in Figure 5; this results in clockwise rotation of arm II1 around its pivot I5I and consequently the movement of the pivot pin II 4 to the left and movement of toggle III to the left with respect to Figures 4 and 5.

Since the latching link I is now engaged and held rigidly by the latch I22, the toggle III is supported and cannot break upwardly, and movement of the toggle I I I to the left opens the maker. On completion of the opening movement, the toggle I is broken slightly up through center, being prevented from collapsing upwardly by the blocking members I10 and HI, and the elements of the circuit maker are held in the open position preparatory to a tripping operation.

The handle I8I is inserted in the socket I83 Slot I90 is provided with a cover I9I which is pivotally mounted at I92 so that it may be swung down out of the way to permit the introduction of the handle I8I. This cover I9I may be locked in position against unauthorized operation of the circuit maker by a padlock going through matching loops I94 on the panel I01 and on the cover I9I.

The side frames I00 of the circuit maker are rigidly cross-braced by the cross braces 62, 80 and I09, as previously pointed out as well as by the cross brace 19, and 2I0. Cross braces 62 and 19 rigidly carry the connecting member I0 which is secured thereto by the bolts 200. Additional angle members 20I and 202 are also provided for rigidity. Similarly, for rigidification, the cross brace 80 issecured to the insulating block 8| by bolts 203. 203, and this block rigidly braces the connecting bar 55. The balks 11 and 18 rigidly space the connecting members I0 and 55 with respect to each other. The cross brace 2 I0 and cross angle member 2II rigidly position the connecting block II and connecting elements I2 with respect to other elements or the circuit maker. Members 2 I0 and 2 are interconnected with the connecting elements II and I2 by suitable bolts H3.

The operating arm II1 has an adjustable stop 222 which bears against the cross member 223 of the intermediate arm 220.

When the circuit maker is tripped and the toggle III collapses, the operating arm H1 is rotated in a clockwise direction while the intermediate arm 220 remains stationary. When the device is re-set by the clockwise rotation of the arm I80, the toggle I55 is broken downward (Fig. 4) and the intermediate arm 220 rotates counterclockwise. This motion permit the operating arm II1. to straighten the toggle III and drop the latch engaging roller I2I under the latch member I22 from the position in Figure 6 to the position in Figure 4.

The toggle III is prevented from passing over center below the points II3 and H6 by the adjustment of the bell crank 225. The bell crank 225 is fastened to the toggle III through the latching link I20 and the pivot point I2I. It is adjusted by the abutment 226 bearing against the adjustable stop 228.

My novel circuit maker may, of course, be provided with various control elements which integrate its operation with that of various other members. Thus, for instance, a control switch 230 may be mounted on the panel I01 having appropriate connections 23I and 232. The control switch is operated by a crank 235 which in turn is operated by the link 231 connected at 238 to the bell crank lever 239. The bell crank lever 239 is pivotally rotatable around an extension of the main contact arm pivot I9 and has an arm 240 which extends substantially parallel with the contact arm 20 and bears against an extension of the pivot rod II3. Consequently, any movement of the contact arm 20 about its pivot I9 results in corresponding rotation of the bell crank lever 239 about the pivot I9 and corresponding movement of the link 231 and actuation of the control switch 230.

In Figure 7 I have shown schematically one manner in which my novel circuit maker may be used where the source of supply is cut off either by failure of the source of supply or by the opening of a circuit breaker or by a short circuit.

The reactance of the load may damage elements of the load itself or of its connecting members. The circuit maker is so arranged, however, as previously described, that it will trip under the same conditions as will result in an opening of the current from the source of supply. The

circuit maker, however, will trip closed under these conditions and will provide a by-pass for the voltage induced by the reactance of the load on cutting off of the source of supply. This by-pass will permit the necessary voltage drop to occur without damage to the winding of the load. The load, of course, need not necessarily be limited to an electric magnet, but any load which will tend to create a voltage of relatively high potential on instantaneous cutting off of the source of supply may be protected in the same manner. In addition, where circumstances and design require it, a resistance R may be inserted in series with the circuit maker to reduce the voltage on closing of the circuit maker.

In Figure 8, I have shown a reproduction of an oscillogram demonstrating the operation of my device. The bottom line shows the trip coil current, that is, the current in the principal circuit, not in the by-pass circuit. The second line from the bottom shows the voltage across the contacts of the circuit maker. The third line from the bottom shows the current across the contacts of the circuit maker; while the top line shows the generator voltage in the principal circuit. It will thus be seen that by the time the trip coil current (the current in the principal circuit) reaches a value X, the circuit maker contacts have closed (second line from bottom) and the voltage across the contacts of the circuit maker has dropped. At the same time. of course, as shown by the third line from the bottom, the fiow of current across the contacts of the circuit maker is established and current fiows until the discharge of the voltage across the load is completed. The trip coil current continues to rise beyond the point X until the arc of the circuit breaker which protects the source of supply is extinguished; this allows time for a drop in the generator voltage as shown at Y of Figure 8. The oscillogram here shown shows a return to voltage zero within 78 cycles or less than 1.3 seconds.

In the foregoing. I have described my invention only in connection with a specific preferred embodiment thereof. Many variations and modifications of my invention should now be obvious to those skilled in the art. Accordingly, I prefer to be bound not by the specific disclosures herein but only by the appended claim.

I claim:

In a circuit maker having a fixed contact and a movable contact, said movable contact being movable with respect to the other, a main movable arm carrying said movable contact and having a first position in which said contacts engage and having a second position in which said contacts disengage, said main movable arm being movable from its second to its first position, studs providing a current path to said movable arm and its contact and to the other of said contacts, said current path from one of said studs to said arm and through the other contact to the other stud forming a loop circuit, said movable arm in its contact open position being within said loop and having a path of movement about its cm 10 pivot when moving from its contact open to its contact engaging position, which path of movement is continuously within said loop and toward completion of said loop and a closing mechanism for applying a force for moving said movable arm in a direction from the second contact disengaged position within said loop toward the first contact engaging position at said loop. the magnetic forces on said main movable arm, due to the current flowing in said circuit maker, on engagement of said contacts being in the direction to drive said main arm toward said loop completion position and in the same direction as the forces of said closing mechanism which together with the magnetic forces are acting simultaneously to maintain the movable arm in contact engaging position.

OTTO JENSEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 494,808 Van Denburgh Apr. 4, 1893 771,307 Hewlett Oct. 4, 1904 809,318 Burnham Dec. 5, 1905 808,371 Horry Dec. 26, 1905 30 1,218,887 Smith Feb. 20, 1917 1,310,353 Kovacs July 15, 1919 1,727,831 Bruhlmann Sept. 10, 1929 1,854,990 Hilliard Apr. 19, 1932 2,127,813 Graves Aug. 23, 1938 2,275,891 Cox et a] Mar. 10, 1942 2,283,748 Mathieu May 19, 1942 2,329,003 Seaman Sept. 7, 1943 FOREIGN PATENTS 4 Number Country Date 322,057 France June 18, 1902 11,168 Great Britain May 14, 1904 442,788 Germany Apr. 8, 1927 473,386 Germany Mar. 14, 1929 

